Early Evaluation of Tumoral Response to Antiangiogenic Therapy by Arterial Spin Labeling Perfusion Magnetic Resonance Imaging and Susceptibility Weighted Imaging in a Patient With Recurrent Glioblastoma Receiving Bevacizumab

Receiving Bevacizumab Case ReportA 79-year-old man with recurrent glioblastoma was treated with bevacizumab (10 mg/kg) and irinotecan (125 mg/m 2 ) every 2 weeks for 6 months.He did not receive corticosteroids during this period.The patient underwent a multimodal magnetic resonance imaging (MRI) protocol before treatment (D0) and 15, 30, 90, 120, and 180 days after treatment (D15, D30, D90, D120, and D180, respectively).The MRI study was approved by our institutional committee on ethics, and informed consent was obtained from the patient.Before treatment, fluid-attenuated inversion recovery (FLAIR) abnormalities covered almost all of the right hemisphere (mass effect), and the product of the maximal perpendicular diameters of enhancing lesion was evaluated at 47 ϫ 61 mm 2 (Figs 1A and 1E).During the first month after beginning therapy (Figs 1B, 1C, 1F, and 1G), the patient experienced reduced contrast enhancement (CE) and FLAIR hyperintensity compared with baseline (Figs 1C, 1G, and 2, ASL, arterial spin labeling; DSC, dynamic susceptibility contrast; rCBF, regional cerebral blood flow; rCBV, regional cerebral blood volume; SWI, susceptibility weighted imaging) and was described as clinically stable by the neurooncologist.However, quantitative data from ASL perfusion MRI, DSC MRI, and SWI showed increased tumor blood flow, blood volume, and vascularization, respectively, in favor of tumor progression (Fig 2).There was also an area of high CBF on ASL maps (Fig 3E, red arrow) not associated with CE (Fig 3B).Figures 3A through 3F show the evolution of the tumor.MRI examination performed 2 months later (D90) demonstrated a large increase of enhancing lesion, whereas edema continued to decrease (Figs 1D, 1H, and 2).